Coordination among respiratory, laryngeal and supralaryngeal articulators in normal speech production will be examined using a broad range of techniques. Explicit models of coarticulation will be tested over prosodic variations. Basic sensory motor interactions in the control of the speech motor system will be studied within the framework of control process for skilled action. Speech in disorders implicating defective control processes in stuttering and the speech of the hearing impaired will be compared with reference to normal production. A computational model of speech production will be further developed including interface with an articulatory speech synthesizer generating acoustic output. Physiological and optical methods will be used to improve the model implementation. Serial application of neural net techniques will be explored in the modeling.